Suppose you are given an op amp and 20 resistors, each with resistance R. Assuming ideal op-amp behavior, design a circuit which, given input voltages v1, v2, v3, and v4, will deliver a voltage vo, given by vo = 2v1 + 4v2 -2v3-4v4 to a load resistor RL. Your answer should include a drawing of the circuit diagram for your op-amp circuit, including the load resistor and all input voltages, and an analysis showing that the circuit performs the desired function. Note that you may not need to use all the resistors provided.